Fusing clip for bifocal lenses



G. A. CLEMENT FUSING CLIP FOR BIFOCAL LENSES Filed August 13, 1925 June 239 1926. 1,590,673

" I N VEN TOR. M 4 M A TTORNEYS Patented June 29, 1926.

U IT E D S TA T S.

OFF'I GEORGE A- T. or MOUNT. rs wcn New YQRK, ASSIGNQR o DUALUXE M- PANY, me, a ooerolterrou or DELAWARE.

rnsrne our son BIro'cAL enses.

Application filed August 1 3, 1925. Serial No. 50,084.

My invention relates to means for prop erly holding the parts of fused bifocal lens blanks during the fusingoperation Such blanks are ordinarily made by fusing a but- 6 tonv or segment of flint glass on. to aseat prepared in the surface of a major lens. blank consisting of a block or disc of crown glass, and the finished lens is thereafter formed from the blank. the face. in which the segment is fused being ground and polished down. to a smooth surfaceof'continuous curvature, and the other side being. shaped: according to prescription. lihe area which in-v cludes the segment constitutes. the, strongerv or reading lens portion of they bifocal. lens.

In the manufacture of such blanks, the seat for the button orsegment is prepared onthe major lens by grinding and polishing" contacts at or near its outer edges. As it sofa tensand drops down thereforeunder-the action of the heat, it will gradually sink from.

the original point of contact and progresr.

sively and outwardly enlarge. its area of contact, and, inthat way, avoid the: entrapping of the air-and gases formed; during the fusing operation.

It is important toprevent the button from shifting on its seat after it has been finally placed preparatory to fusing, and it is desirable that any holding means employed; for this purpose should be able to. adapt itself to the relative positions of the seat. onthe various sizes of blanks.

In accordance. with my invention, I em-.

ploy a fusing block of refractory material upon which the major lens blank is placed:

with the seat prepared usually'at one edge thereof, and I provide. an archedeshaped stop member adjustably carried by. the. block so,

that it can be brought across, the seat and properly position the. button thereon. This surface of'the-major lens blank, and also. to

segment-positioning or stop member may con'venlently be part of a wire bowed spring.

clip, the ends. of which bear frictional-1y,

against the sides ofthe block and the center of which is bent up to form the segment-positioning portion. Cooperative with this po-v sitioning member is a pressure device which bears on the top of the segment between the uprights of the arched portion and tilts. the segment on its seat.

I shall now. describe the illustrated: em-. bodiment of my invention and shall thereafter point out my invention in claims.

Fig. l is a plan view of a suitable segmentpositioning member,

Fig. 2 is a side elevation of the same.

Fig. 3- is a side elevation of one form of pressure device for tilting the se ment.

Figs. 4 and 5 are, respectively, a side elevation and plan of a complete assembly embodyingv my invention as used with a wide angle: segment.

Figs. 6 and 7 are corresponding views of an assembly as used with a round segment. i

The fusing block 1 of. carborundum or other 'suitablematerial is thicker at one edge than at the other so that its top sur face is inclined, although it will be under: stood that this surface configuration of the block is not an essential part of my invene tion. The major blank 2 which is supported on this block is shown as concavo convex in form and the top surface of the block 1: is correspondingly convexed'. If desired, a step may be provided on each of the lower corners of the block to facilitate the positioning of the major blank thereon, but such stops, while convenient, are not n-ec es sary and are therefore not: shown. The seat 32 for the segment 4 is formed on the convex side of themajor lens blank, a segmental portion being finished off from the edgev to near the center of the blank. The buttons are shown as more nearly plano, since the seat 3 is shown as a convex spherical or plus surface, and the buttons have their under surfaces ground: and polished so as to properly fuse with the surface of the seat as the button drops down. to the conformation-of the. seat.

Toproperlyposition the button on its seat, a stop member is employed of the character shown. in Figs. 1 and 2. This is a bowed spring wire member of substantially bail 7 blank.

shape or U-shape, the two arms 5 and 6 terminating in looped ends, and the intermediate or cross part having its m1ddle portion bent or arched up to form a segment-posisubstantially greater than the combined thickness of the major. lens blank and of the segment. I 1

The major lens blank 2 is shown as placed on the block 1 with the seat for the segment disposed at the higher side. The seat 1s thereby substantially horizontal. The w re stop member is placed upon the block with the two arms frictionally gripping the sides of the block which gripis augmented by the looped ends, and it is adjusted on the block so that the intermediate portion crosses over the higher side of the face of the major lens This brings the arch-ed portion 7 over the outer edge of the seat, and the segment is then placed onthe seat against the uprights of the arch, and is in that way properly positioned on its seat; 'When the wide angle segment 1 is used,-the stopinember rests upon theblockl, as shown in Figs. 4 and 5. WVhen a round segment 4 is used, the stop member is placed upon the major lens blank, as shown in Figs. 6 and '7, since the round segment is smaller and will project farther through the arched portion of the segment. The adjustability of the stop member on the block permits of this alternative disposition of the segment-positioning,

, arch 7.

In order to tilt the segment on its 1 seat a pressure device is used, such, for example, as shown in detailin Fig. 3. In the illustrated form this consists of a hook-shaped, wire spring clip 8, the long arm of which is straight and in the fusing assembly bears in a narrow central longitudinal slot 9-in the bottom of the block 1, while the hooked end bears with its point on top of the segmentnear its outer edge which may have a slight recess formed to receive the point.

The parts may be quickly assembled with assurance that the two lens parts will be properly related. The whole assembly may then be picked up and moved with the exercise of a little care without displacing the segment. The conventional fusing block requires no substantial change for use in my assembly and there is nothing in the assembly to be injured bythe heat.-

It is obvious that various modification may be made in the construction shown in the drawings and above particularly described within the principle and scope of my invention.

I claim: 7

1. For fusing bifocal lenses composed of amajor lens and 'a segment fused on a seat formed in the surface of the major lens, means for holding the parts while fusing comprising a supporting block for the major lens, and a Usshaped segment-positioning member adapted to span the block with its intermediate portion and frictiona-lly engage the sides of'the'block with its ends and having its middle portion upwardly arched for a width less than that of a segment. J

2. For fusing bifocal lenses composed of a major lens and a segment fused on a seat formed in the surface of the major lens, means for holding the parts while fusing comprising a'supporting block forthe major lens, and a resilient wire segment-positioning member of U-shape adapted to span the block with its intermediate portion and fric- Y tionally engage the sides of the block with" its ends and having its middle portion up wardly arched for a width less than that of a segment.

3. For fusing bifocal lenses composed of a major lens and a segment fused on a seat formed in the surface of the major lens, means'forholding the parts while fusing comprising a supporting block for the major lens, a U -shaped segment-positioning member adapted to span the block with its intermediate portion and frictionally engage the sidesof the block with its ends .and having its middle portion upwardly arched for a width less than that of a segment, and a pressure device adapted to bear on the top of a segment positioned within the said arched portion and tilt the sameon its seat. 4. For fusing bifocal lensescoinposed of a major lens and a segment fused on a seat formed in the surface of the major lens, means for'holding the parts while fusing comprising a supporting block for the major lens,-a U-shaped segment-positioning member adapted to span the block with its intermediate portion and frictionally en age the sides of the block with its ends and aving its middle portion upwardly arched for a width less than that of a segment, and a hook-shaped spring clip adapted to bear on the underside of the block with one end and having a downwardly directed point on the other end adapted to bear on the top of a segment near its outer edge within the said arched portion and tilt the same on its seat.

5, For fusing bifocal lenses composed of a major lens and a segment fused on a seat formed in the surface of the major lens, means for holding the parts while fusing comprising a supporting block for the major lens, a resilient Wire segment-positioning member of U-shape adapted to span the block with its intermediate portion and frictionally engage the sides of the block with its ends and having its middle portion upwardly arched for a Width less than that of a segment, and having thecross-piece of the arch bent inwardly, and a. hook-shaped spring clip adapted to bear on the top of a segment positioned Within the said arched portion and tilt the same on its seat.

6. For fusing bifocal lenses composed of a major lens and a segment fused on a seat formed in the surface of the major lens, means for holding the parts While fusing comprising a supporting block for the major lens, and an arch-shaped segment-positioning member adjustably carried by the block and arranged to rest upon the top of the block near one edge thereof.

In Witness whereof, I hereunto subscribe my signature.

GEORGE A. CLEMENT. 

